In photo- and video-related applications and customer devices, image data are usually pre-processed in order to better adapt the image properties before the images or pictures are displayed or further processed. One aspect is the enhancement of sharpness of the image or picture. A problem when enhancing the sharpness of an image or with respect to other pre-processing steps is that the respective process is in general applied to all image details represented by the image data. However, it is desirable to process image details that originate from noise in a different manner than image details that originate from edges in the image. Accordingly, processes have been established, in order to differentiate between homogenous and non-homogenous image regions.
Methods for classifying signals are, for example, known from EP-A-1 821 417, EP-A-1 840 823, WO 2007/096168 or U.S. Pat. No. 6,771,793.